623640640 has 168 divisors, whose sum is σ = 1784616192. Its totient is φ = 206760960.

The previous prime is 623640617. The next prime is 623640649. The reversal of 623640640 is 46046326.

It is a Harshad number since it is a multiple of its sum of digits (31).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (623640649) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 485439 + ... + 486721.

Almost surely, 2^623640640 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 623640640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (892308096).

623640640 is an abundant number, since it is smaller than the sum of its proper divisors (1160975552).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

623640640 is a wasteful number, since it uses less digits than its factorization.

623640640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1345 (or 1328 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 31.

The square root of 623640640 is about 24972.7980010250. The cubic root of 623640640 is about 854.3676639606.

Adding to 623640640 its reverse (46046326), we get a palindrome (669686966).

The spelling of 623640640 in words is "six hundred twenty-three million, six hundred forty thousand, six hundred forty".